Java&JFreeChart -如何设置一个JFreeChart的ChartPanel大小和它的容器(比如JPanel)的大小?

I just found that when i add a ChartPanel to a JFrame, the ChartPanel will resize to fit the frame as the JFrame dragged larger or smaller. However, when i add the ChartPanel to a JPanel, the JPanel's size( width and height ) changes to fit the JFrame as the JFrame resized. But the ChartPanel just keeps it's dimensions, leaving the enlarged JPanel a lot of empty space. How to make ChartPanel resize with it's container in GUI?I just found that when i add a ChartPanel to a